Normally when a vehicle breaks down or has trouble on the road, the driver can place a conventional triangular light reflecting warning sign behind the troubled vehicle for alert warning. The conventional light reflecting triangular warning sign work fine during daytime or high visibility hours. However, when the weather is rainy or foggy, with low visibility other drivers may fail to observe the warning sign and crash into the troubled vehicle.
The conventional light reflecting triangular warning sign also have the following shortcomings. Most of the conventional light reflecting triangular warning sign is not easy to store because of their sizes. Although the size of the conventional light reflecting triangular warning sign seem too large to fit well in the trunk of the vehicle, when they are placed on the road, they becomes too small to catch the attention of other drivers. The earlier the other drivers can detect the bad road condition ahead, the more reaction time the other drivers may have to avoid the accident.
Another major disadvantage of the conventional light reflecting triangular warning sign is that it do not provide the self-flashing or self-illuminating function. As mentioned above, during low visibility condition, such as the bad weather condition or nighttime, other drivers may not be able to clearly observe the warning signs that would lead to an undesirable accident.